<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<div id="app">
    Hello world!
    <h1 style="display: none">666</h1>
</div>

<p id="p"></p>

<script>
    let app = document.getElementById('app')
    console.log(app.textContent);
    console.log(app.innerText);
    p.textContent = 'textContent'
</script>
</body>
</html>
